In general, a parallel-plate type substrate processing apparatus generates plasma by applying an RF (radio-frequency) voltage to one of a pair of electrodes to process a substrate (i.e., wafer) placed on the electrode to which the RF voltage is applied or on the other electrode.
Two or more technologies to apply a pulse-like positive voltage as bias have been disclosed in order to suppress charging damage and local abnormal etching (i.e., notching) during the substrate processing.